post_href
stringlengths
57
213
python_solutions
stringlengths
71
22.3k
slug
stringlengths
3
77
post_title
stringlengths
1
100
user
stringlengths
3
29
upvotes
int64
-20
1.2k
views
int64
0
60.9k
problem_title
stringlengths
3
77
number
int64
1
2.48k
acceptance
float64
0.14
0.91
difficulty
stringclasses
3 values
__index_level_0__
int64
0
34k
https://leetcode.com/problems/arranging-coins/discuss/1849942/Python-Simple-Solution!
class Solution(object): def arrangeCoins(self, coins): stairs = 0 while stairs <= coins: coins -= stairs stairs += 1 return stairs-1
arranging-coins
Python - Simple Solution!
domthedeveloper
0
34
arranging coins
441
0.462
Easy
7,800
https://leetcode.com/problems/arranging-coins/discuss/1838610/Python3oror-TC%3A-O(log-N)-oror-Binary-Search
class Solution: def arrangeCoins(self, n: int) -> int: #sum of first k natural numbers -> (k*(k+1)) // 2 low, high = 0, n while low <= high: mid = low + (high - low) // 2 coins = (mid*(mid+1)) // 2 if coins == n: return mid elif coins < n: ans = mid low = mid + 1 else: high = mid - 1 return ans #TC: O(logN)
arranging-coins
Python3|| TC: O(log N) || Binary Search
s_m_d_29
0
39
arranging coins
441
0.462
Easy
7,801
https://leetcode.com/problems/arranging-coins/discuss/1587003/Python-O(1)-algebra
class Solution: def arrangeCoins(self, n: int) -> int: from math import sqrt, floor cand = int(floor(sqrt(2*n))) if 2*n-cand>=cand**2: return cand return cand-1
arranging-coins
[Python] O(1), algebra
stefaMVP
0
56
arranging coins
441
0.462
Easy
7,802
https://leetcode.com/problems/arranging-coins/discuss/1567219/python3-Binary-Search-solution-Faster-than-90
class Solution: def arrangeCoins(self, n: int) -> int: #O(logn) time complexity low,high = 1,n while low <= high: mid = (low+high)//2 if ((mid)*(mid+1))/2 > n: high = mid-1 else: low = mid+1 return high
arranging-coins
python3 Binary Search solution - Faster than 90%
sonali1597
0
52
arranging coins
441
0.462
Easy
7,803
https://leetcode.com/problems/arranging-coins/discuss/1561301/Python3-or-Simple-for-loop-Solution-or-Easy-To-Understand
class Solution: def arrangeCoins(self, n: int) -> int: coin = 0 for index in range(1,n+1): coin += index if coin >= n: break if coin > n: index -= 1 return index
arranging-coins
Python3 | Simple for loop Solution | Easy To Understand
Call-Me-AJ
0
35
arranging coins
441
0.462
Easy
7,804
https://leetcode.com/problems/arranging-coins/discuss/1560443/Python-Solution-Brute-Force
class Solution: def arrangeCoins(self, n: int) -> int: if n == 1: return 1 if n == 0: return 0 stairs = [] i = 0 while i < n: if not stairs: stairs.append(1) i += 1 else: curr_step = stairs[-1] + 1 if n - i > curr_step: stairs.append(curr_step) i += curr_step else: stairs.append(n-i) i += n - i complete_steps = len(stairs) if complete_steps > 1: if stairs[-1] == stairs[-2] + 1: return complete_steps else: return complete_steps - 1 else: if stairs[-1] == 1: return 1 else: return 0
arranging-coins
Python Solution - Brute Force
japhethmutai
0
30
arranging coins
441
0.462
Easy
7,805
https://leetcode.com/problems/arranging-coins/discuss/1560406/Python-iterative-solution
class Solution: def arrangeCoins(self, n: int) -> int: count = Sum = 0 while Sum <= n: count += 1 Sum += count return count - 1
arranging-coins
Python iterative solution
abkc1221
0
19
arranging coins
441
0.462
Easy
7,806
https://leetcode.com/problems/arranging-coins/discuss/1461347/Simple-or-python-3
class Solution: def arrangeCoins(self, n: int) -> int: for i in range(1, n+1): n -= i if n == 0: return i if n < 0: return i - 1
arranging-coins
Simple | python 3
deep765
0
208
arranging coins
441
0.462
Easy
7,807
https://leetcode.com/problems/arranging-coins/discuss/1461347/Simple-or-python-3
class Solution: def arrangeCoins(self, n: int) -> int: left, right = 0, n while left <= right: k = (right + left) // 2 curr = k * (k + 1) // 2 if curr == n: return k if n < curr: right = k - 1 else: left = k + 1 return right
arranging-coins
Simple | python 3
deep765
0
208
arranging coins
441
0.462
Easy
7,808
https://leetcode.com/problems/arranging-coins/discuss/1172616/Python3-Simplest-One-Line-Approach-with-Explanation
class Solution: def arrangeCoins(self, n: int) -> int: ''' 1. We need to find an integer x such that 1+2+3+...+x = n-p where p is minimum 2. Using the formula of summation of series, the sum of series 1+2+3+...+x = x(x+1)/2 3. Solve the equation, x(x+1)/2 = n - using solution of quadratic equation (i.e. ax^2+bx+c=0), in this case x = (-1+square_root(1+8n))/2 - as x must be positive integer, take floor of square root of (1+8n) to calculate x and then take floor of x ''' return int((-1+int((1+8*n)**0.5))//2)
arranging-coins
Python3 Simplest One Line Approach with Explanation
bPapan
0
47
arranging coins
441
0.462
Easy
7,809
https://leetcode.com/problems/arranging-coins/discuss/1005788/Why-so-slow
class Solution: def arrangeCoins(self, n: int) -> int: if n<=1: return n x=0 sum1=0 while n>=sum1: x+=1 sum1+=x return x-1
arranging-coins
Why so slow??
thisisakshat
0
80
arranging coins
441
0.462
Easy
7,810
https://leetcode.com/problems/arranging-coins/discuss/714720/Python3-two-approaches-O(logN)-and-O(1)
class Solution: def arrangeCoins(self, n: int) -> int: lo, hi = 0, n while lo <= hi: mid = (lo+hi)//2 if mid*(mid+1)//2 <= n: lo = mid + 1 else: hi = mid - 1 return hi
arranging-coins
[Python3] two approaches O(logN) & O(1)
ye15
0
55
arranging coins
441
0.462
Easy
7,811
https://leetcode.com/problems/arranging-coins/discuss/714720/Python3-two-approaches-O(logN)-and-O(1)
class Solution: def arrangeCoins(self, n: int) -> int: return int((sqrt(8*n + 1) - 1)//2)
arranging-coins
[Python3] two approaches O(logN) & O(1)
ye15
0
55
arranging coins
441
0.462
Easy
7,812
https://leetcode.com/problems/arranging-coins/discuss/524663/Python-3-Simple-O(n)-time-complexity-use-While-loop-not-Math
class Solution: def arrangeCoins(self, n: int) -> int: stairCase = 1 while n >= stairCase: n -= stairCase stairCase += 1 return stairCase-1
arranging-coins
[Python 3] Simple, O(n) time complexity, use While loop, not Math
smiile8888
0
270
arranging coins
441
0.462
Easy
7,813
https://leetcode.com/problems/arranging-coins/discuss/362161/Solution-in-Python-3-(beats-~98)-(one-line)
class Solution: def arrangeCoins(self, n: int) -> int: return int(((1+8*n)**.5 - 1)/2) - Junaid Mansuri (LeetCode ID)@hotmail.com
arranging-coins
Solution in Python 3 (beats ~98%) (one line)
junaidmansuri
0
272
arranging coins
441
0.462
Easy
7,814
https://leetcode.com/problems/arranging-coins/discuss/336759/Python-solution-using-math-and-binary-search
class Solution: def arrangeCoins(self, n: int) -> int: if n < 1: return 0 low = 0 high = n mid = 0 while low <= hi mid = low + (high - low) // 2 s = (mid**2 + mid) >> 1 if s > n: high = mid - 1 elif s < n: low = mid + 1 else: return mid if (mid**2 + mid) >> 1 > n: mid -= 1 return mid ```
arranging-coins
Python solution using math and binary search
ultrablue
0
125
arranging coins
441
0.462
Easy
7,815
https://leetcode.com/problems/arranging-coins/discuss/1444929/Python3-One-Line-Math-Solution-Faster-Than-96.32
class Solution: def arrangeCoins(self, n: int) -> int: return int((2 * n + (1 / 4)) ** 0.5 - 1 / 2)
arranging-coins
Python3 One-Line Math Solution Faster Than 96.32%
Hejita
-1
54
arranging coins
441
0.462
Easy
7,816
https://leetcode.com/problems/arranging-coins/discuss/1175510/WEEB-DOES-MATH-WITH-BINARY-SEACH
class Solution: def arrangeCoins(self, n: int) -> int: low, high = 1, 65536 while low < high: mid = low + (high-low)//2 if 0.5 * mid**2 + 0.5 * mid == n: return mid if 0.5 * mid**2 + 0.5 * mid > n: high = mid else: low = mid + 1 return low - 1
arranging-coins
WEEB DOES MATH WITH BINARY SEACH
Skywalker5423
-3
171
arranging coins
441
0.462
Easy
7,817
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/396890/Two-Solutions-in-Python-3-(-O(n)-time-)-(-O(1)-space-)
class Solution: def findDuplicates(self, N: List[int]) -> List[int]: S, A = set(), [] for n in N: if n in S: A.append(n) else: S.add(n) return A
find-all-duplicates-in-an-array
Two Solutions in Python 3 ( O(n) time ) ( O(1) space )
junaidmansuri
9
1,700
find all duplicates in an array
442
0.734
Medium
7,818
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/396890/Two-Solutions-in-Python-3-(-O(n)-time-)-(-O(1)-space-)
class Solution: def findDuplicates(self, N: List[int]) -> List[int]: A = [] for n in N: if N[abs(n)-1] > 0: N[abs(n)-1] = -N[abs(n)-1] else: A.append(abs(n)) return A - Junaid Mansuri (LeetCode ID)@hotmail.com
find-all-duplicates-in-an-array
Two Solutions in Python 3 ( O(n) time ) ( O(1) space )
junaidmansuri
9
1,700
find all duplicates in an array
442
0.734
Medium
7,819
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2830285/using-defaultdict
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: dc=defaultdict(lambda:0) for a in nums: dc[a]+=1 ans=[] for a in dc: if(dc[a]==2): ans.append(a) return ans
find-all-duplicates-in-an-array
using defaultdict
droj
4
47
find all duplicates in an array
442
0.734
Medium
7,820
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2726787/Python-oror-O(1)-oror-Beginners-Solution-oror-Easy
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: ans = [] for i in range(len(nums)): if nums[abs(nums[i])-1]>0: nums[abs(nums[i])-1] = -nums[abs(nums[i])-1] else: ans.append(abs(nums[i])) return ans
find-all-duplicates-in-an-array
Python || O(1) || Beginners Solution || Easy
its_iterator
3
542
find all duplicates in an array
442
0.734
Medium
7,821
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1433147/Python-O(n)-without-extra-space
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: for i in range(len(nums)): index = (nums[i]%len(nums))-1 #As value from 1-n nums[index]+=len(nums) output = [] for i,v in enumerate(nums): if v>2*len(nums): output.append(i+1) return output
find-all-duplicates-in-an-array
Python O(n) without extra space
abrarjahin
2
263
find all duplicates in an array
442
0.734
Medium
7,822
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2213708/Python-solution-with-in-depth-explanation-of-the-algorithm-and-comments-for-each-line-of-code
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: # output result array (which won't be counted as per description of the given problem.) res = [] # Iterating through each element in the given array for num in nums: at_index = abs(num) - 1 # Getting the index one point less since index starts with zero than the current element for e.g.: n = 4 , so index = 4 - 1 = 3 so on and so forth. (for more in depth explanation read algorithm part at the top) if nums[at_index] < 0: # checking if the current number is already negative then the current element is a duplicate res.append(abs(num)) # Hence add it to the result array else: nums[abs(num) - 1] *= -1 # If it's not a negative then we're visiting it for the first time hence mark it visited by making element a negative number return res
find-all-duplicates-in-an-array
Python solution with in-depth explanation of the algorithm and comments for each line of code
pawelborkar
1
69
find all duplicates in an array
442
0.734
Medium
7,823
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/775662/Python-or-Easy-2-solutions-(1-Line-and-using-dict)
class Solution(object): def findDuplicates(self, nums): letter,res = {},[] for i in nums: if i not in letter: letter[i]=1 else: letter[i]+=1 for i,j in letter.items(): if j>1: res.append(i) return res
find-all-duplicates-in-an-array
Python | Easy 2 solutions (1 Line and using dict)
rachitsxn292
1
418
find all duplicates in an array
442
0.734
Medium
7,824
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/775662/Python-or-Easy-2-solutions-(1-Line-and-using-dict)
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: return [x for x, y in Counter(nums).items() if y> 1]
find-all-duplicates-in-an-array
Python | Easy 2 solutions (1 Line and using dict)
rachitsxn292
1
418
find all duplicates in an array
442
0.734
Medium
7,825
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/242426/Python-2-line
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: count = collections.Counter(nums) return [key for key,val in count.items() if val == 2]
find-all-duplicates-in-an-array
Python 2 line
tinaaggarwal
1
377
find all duplicates in an array
442
0.734
Medium
7,826
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2814615/Medium-seriously
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: d = Counter(nums) res = [] for k, v in d.items(): if v == 2: res.append(k) return res
find-all-duplicates-in-an-array
Medium, seriously?
mediocre-coder
0
3
find all duplicates in an array
442
0.734
Medium
7,827
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2804234/python3-O(n)-time-O(1)-space-with-down-to-earth-explanation
class Solution: # the requirement of 1 <= nums[i] <= n is crucial. because # of this requirement, we can move each val to its own position. # say we have [3,1,2], then for value 3 we expect it to move to # nums[3], value 2 at nums[2], etc. so result would be # [0,1,2,3]. each value stays at its own place, you gotta know # your place man. If you are trying to move to your place, but # your duplicate occupied it first, like if we have [0,3,2,3], # you are nums[1] == 3, and you are trying to move to nums[3] # but nums[3] == 3 is already there, then you know # he is a duplicate and you kick him to result. def findDuplicates(self, nums: List[int]) -> List[int]: res = [] nums.append(0) for i in range(len(nums)): while nums[i] and nums[i] != i: if nums[nums[i]] == nums[i]: res.append(nums[i]) nums[i] = 0 else: nums[nums[i]], nums[i] = nums[i], nums[nums[i]] return res
find-all-duplicates-in-an-array
python3 O(n) time, O(1) space with down to earth explanation
tinmanSimon
0
3
find all duplicates in an array
442
0.734
Medium
7,828
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2797121/PYTHON3-BEST
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: a=[] for i in nums: i = abs(i) if nums[i-1] < 0: a.append(i) else: nums[i-1] = -nums[i-1] return a
find-all-duplicates-in-an-array
PYTHON3 BEST
Gurugubelli_Anil
0
3
find all duplicates in an array
442
0.734
Medium
7,829
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2785861/Beats-100-constant-space
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: ans = [] for i in range(len(nums)): if nums[abs(nums[i])-1] <0 : ans.append(abs(nums[i])) nums[abs(nums[i])-1] *= -1 return ans
find-all-duplicates-in-an-array
Beats 100% constant space
sanskar_
0
10
find all duplicates in an array
442
0.734
Medium
7,830
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2778666/Python-solution-using-dictionary.
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: dic={} ans=[] for i in nums: if i in dic: dic[i]=dic[i]+1 else: dic[i]=1 for i in dic: if dic[i]>1: ans.append(i) return ans
find-all-duplicates-in-an-array
Python solution using dictionary.
zaeden9
0
1
find all duplicates in an array
442
0.734
Medium
7,831
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2758456/Official-solution-is-wrong-REAL-O(1)-space-Solution
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: # Pointer to write our result into nums j = 0 # Mark a number x as seen, by inverting the value at index x for x in nums: # If seen before, it is part of our result if nums[abs(x)-1] < 0: # The value at j may carry information about another number # so we should not change the sign nums[j] = abs(x) if nums[j] > 0 else -abs(x) j+=1 else: nums[abs(x)-1] *= -1 # Once we processed all numbers, it is safe to override all signs for i in range(j): nums[i] = abs(nums[i]) return nums[:j]
find-all-duplicates-in-an-array
Official solution is wrong - REAL O(1) space Solution
LongQ
0
4
find all duplicates in an array
442
0.734
Medium
7,832
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2731291/Easy-python-solution-using-dictionary
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: d = {} for i in nums: d[i] = d.get(i, 0) + 1 ans = [x for x, v in d.items() if v == 2] return ans
find-all-duplicates-in-an-array
Easy python solution using dictionary
_debanjan_10
0
4
find all duplicates in an array
442
0.734
Medium
7,833
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2725771/Python-5-Lines-solution-or-99.51-Faster-or-Easy-solution!!!
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: d=Counter(nums) l = list(map(lambda x:x[0],filter(lambda x:x[1]>1,d.items()))) return l
find-all-duplicates-in-an-array
Python 5 Lines solution | 99.51% Faster | Easy solution!!!
sanjay24685
0
6
find all duplicates in an array
442
0.734
Medium
7,834
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2708557/Python-Easy-Solution-or-O(n)-timeor-Hashmap
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: dictionary={} res=[] for n in nums: if dictionary.get(n,0)==0: dictionary[n]=1 else: res.append(n) return res ```
find-all-duplicates-in-an-array
Python Easy Solution | O(n) time| Hashmap
mjk22071998
0
6
find all duplicates in an array
442
0.734
Medium
7,835
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2691358/Python-solution
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: arr = dict() listof =[] for i in range(len(nums)+1): arr[i] =0 for num in nums: if num in arr: arr[num]+=1 else: arr[num] =1 for key, val in arr.items(): if val > 1: listof.append(key) return listof
find-all-duplicates-in-an-array
Python solution
Sheeza
0
3
find all duplicates in an array
442
0.734
Medium
7,836
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2686156/Two-Pointer-and-Cyclic-Sort-Solutions
#-Two Pointer Solution---------------------------------------------- class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: nums.sort() back = 0 count = 0 for front in range(0, len(nums) - 1): if nums[front] == nums[front + 1]: nums[back] = nums[front] back += 1 count += 1 return nums[: count] #-Cyclic Sort Solution----------------------------------------------- class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: N = len(nums) index = 0 # 1) Perform Cyclic Sort, value at index should (index + 1) while index < N: temp = nums[index] - 1 if nums[index] != nums[temp]: nums[index], nums[temp] = nums[temp], nums[index] else: index += 1 back = 0 # 2) If after sort, (index + 1) value is not present at index, # then store the value in the left of the array. for i in range(len(nums)): if i + 1 != nums[i]: nums[back] = nums[i] back += 1 return (nums[ : back][::-1])
find-all-duplicates-in-an-array
Two Pointer and Cyclic Sort Solutions
user6770yv
0
9
find all duplicates in an array
442
0.734
Medium
7,837
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2666828/3-line-answer-using-Counter-and-list-comprehension
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: # Counter to get the frequency of the elements. occurance = Counter(nums) # If frequency is 2 then add the elements in the list. ans = [x for x in occurance.keys() if occurance[x] == 2] return ans
find-all-duplicates-in-an-array
3 line answer using Counter and list comprehension
24Neha
0
28
find all duplicates in an array
442
0.734
Medium
7,838
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2660809/Python3-or-cyclicsort
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: i=0 #sorting nums by ignoring duplicates while i<len(nums): crt=nums[i]-1 if nums[i]<=len(nums) and nums[crt]!=nums[i]: nums[crt],nums[i]=nums[i],nums[crt] else: i+=1 print(nums) #checking where index=value-1 ==> nums[i]=i+1 s=[] for i in range(len(nums)): if nums[i]!=i+1: s.append(nums[i]) return s
find-all-duplicates-in-an-array
Python3 | cyclicsort
19pa1a1257
0
22
find all duplicates in an array
442
0.734
Medium
7,839
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2658372/easy-using-counter
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: c=Counter(nums) res=[] for i,j in c.items(): if(j >1): res.append(i) return res
find-all-duplicates-in-an-array
easy using counter
Raghunath_Reddy
0
2
find all duplicates in an array
442
0.734
Medium
7,840
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2601989/Python-Solution-using-Counter
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: myDic = Counter(nums) ans = [] for i in myDic: if myDic[i] == 2: ans.append(i) return ans
find-all-duplicates-in-an-array
Python Solution using Counter
mayank0936
0
68
find all duplicates in an array
442
0.734
Medium
7,841
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2545502/python-simple-solution
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: d = defaultdict(int) for n in nums: d[n] += 1 output = [] for i in d: if d[i] > 1: output.append(i) return output
find-all-duplicates-in-an-array
python simple solution
gasohel336
0
79
find all duplicates in an array
442
0.734
Medium
7,842
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2523338/constant-space-solution
class Solution: # one method for constant space and linear time # def findDuplicates(self, nums: List[int]) -> List[int]: # result = [] # for i in range(len(nums)): # if nums[abs(nums[i])-1] < 0: # result.append(abs(nums[i])) # else: # nums[abs(nums[i])-1] *= -1 # return result #other method for constant space and linear time #we will add array_length to particular index element is index element has the value more than two times of the array index than that index element is duplicate # convert array elements same as index element but this step is not necessary def findDuplicates(self, nums: List[int]) -> List[int]: result = [] length_nums = len(nums) for i in range(length_nums): nums[i] -= 1 for i in range(length_nums): index = nums[i] % length_nums nums[index] += length_nums for i in range(length_nums): if nums[i] >= 2*length_nums: result.append(i+1) return result
find-all-duplicates-in-an-array
constant space solution
pg902421
0
57
find all duplicates in an array
442
0.734
Medium
7,843
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2507507/Simple-python-code-with-explanation
class Solution: #if you find word --> (duplicates) in question best way to approach that question most of the times is using --> dictionary def findDuplicates(self, nums: List[int]) -> List[int]: #create an empty dictionary using culy braces thoma = {} #store the keys of dictionary(thoma) in variable -->(k) k = thoma.keys() #iterate over the elements in array --> nums for i in nums: #if element not in k(keys of dictionary) if i not in k: #it means it is new element \ #assingn val 1 to that element thoma[i] = 1 #if element is in k(keys of dictionary) else: #that means it is occured already one time or few times #increase the val 1 to that element which is already having a value thoma[i] = thoma[i] + 1 #create a new list koushik = [] #iterate over the keys in dictionary -->(thoma) for i in thoma: #if the value of key is greater than one if thoma[i] > 1: #it means that it occured more than once #so add that element to the list --> (koushik) koushik.append(i) #after adding all the elements which are repeating more than once #return the list -->(koushik) return koushik
find-all-duplicates-in-an-array
Simple python code with explanation
thomanani
0
53
find all duplicates in an array
442
0.734
Medium
7,844
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2474330/Python-Solution
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: ansList = [] for i in range(len(nums)): index = abs(nums[i])-1 if nums[index] < 0: ansList.append(index+1) else: nums[index] = -1 * nums[index] return ansList
find-all-duplicates-in-an-array
Python Solution
DietCoke777
0
40
find all duplicates in an array
442
0.734
Medium
7,845
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2365320/easy-python-solution
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: unique, duplicate = {}, [] for num in nums : if num not in unique.keys() : unique[num] = 1 else : duplicate.append(num) return duplicate
find-all-duplicates-in-an-array
easy python solution
sghorai
0
84
find all duplicates in an array
442
0.734
Medium
7,846
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2350931/Python-or-Generator-or-Constant-extra-space
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: def duplicator(nums): for idx in range(len(nums)): cur = abs(nums[idx]) - 1 if nums[cur] < 0: yield abs(nums[idx]) nums[cur] *= -1 return [num for num in duplicator(nums)]
find-all-duplicates-in-an-array
Python | Generator | Constant extra space
Sonic0588
0
65
find all duplicates in an array
442
0.734
Medium
7,847
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2296799/O(1)-space-and-O(n)-time-using-heterogeneous-list-of-characters-(no-auxoutput-array)
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: #print(id(nums)) # use fact that lists can contain heterogeneous values seen_twice=0 # mark the index corresponding to a value between 1 and n # make it -1* original value if it's seen once # make it a character if it's seen twice # numbers seen 0 times will be unchanged for idx,n in enumerate(nums): # if the value has been seen twice for this index if isinstance(n,str): nval=ord(n)-ord('a') # if the value has been seen fewer than 2 times else: nval = n # get the value in the array so we can update the corresponding array index absn = abs(nval) pos=absn-1 if nums[pos] > 0 : nums[pos]*=-1 else: # turn the value into a char nums[pos]=chr(abs(nums[pos])+ord('a')) seen_twice+=1 # if all items have been seen once if seen_twice == 0: return [] # remap chars to indexes, and non-chars to 0 value (input values start from 1) for idx, i in enumerate(nums): if isinstance(i,str): nums[idx]=idx+1 else: nums[idx]=0 # use two pointers move the repeated elements to the front of the list # so list can be popped from the back without allocating more memory next_free = 0 next_repeated = len(nums)-1 while next_free < next_repeated: while nums[next_free] > 0: next_free+=1 while nums[next_repeated] < 1: next_repeated-=1 if next_free < next_repeated: nums[next_free],nums[next_repeated]=nums[next_repeated],nums[next_free] # get ready for the next iteration next_free+=1 next_repeated-=1 else: break # pop from the back, leaving only elements seen twice while len(nums) > seen_twice: nums.pop() #print(id(nums)) return nums
find-all-duplicates-in-an-array
O(1) space and O(n) time using heterogeneous list of characters (no aux/output array)
Tsjfienod
0
73
find all duplicates in an array
442
0.734
Medium
7,848
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2197419/Python3-HashMap-%2B-Heap
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: s={} k=[] for i in range(len(nums)): if nums[i] not in s: s[nums[i]] = 1 else: heapq.heappush(k,nums[i]) return k
find-all-duplicates-in-an-array
Python3 HashMap + Heap
aditya_maskar
0
25
find all duplicates in an array
442
0.734
Medium
7,849
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2156966/Python-one-line-solution
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: return [k for k,v in Counter(nums).items() if v>1]
find-all-duplicates-in-an-array
Python one line solution
writemeom
0
75
find all duplicates in an array
442
0.734
Medium
7,850
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2156966/Python-one-line-solution
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: freq = Counter(nums) return [i for i in freq if freq[i]==2]
find-all-duplicates-in-an-array
Python one line solution
writemeom
0
75
find all duplicates in an array
442
0.734
Medium
7,851
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2131155/Python-conventional-method-but-slow
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: output=[] dic ={} for num in nums: if num not in dic: dic[num]=1 else: dic[num]+=1 for key in dic: if dic[key]==2: output.append(key) return output
find-all-duplicates-in-an-array
Python conventional method but slow
M_D
0
24
find all duplicates in an array
442
0.734
Medium
7,852
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2131147/Very-slow-python-method
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: output=[] for i in range(len(nums)): pointi= abs(nums[i])-1 nums[pointi]=-nums[pointi] if nums[pointi]>0: output.append(pointi+1) #真正要return的是这个位置上的数+1 return output '''
find-all-duplicates-in-an-array
Very slow python method
M_D
0
17
find all duplicates in an array
442
0.734
Medium
7,853
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/2045280/Python-3-Solution-O(n)-Time-and-O(1)-Space
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: dups = list() for i in nums: idx = abs(i) - 1 if nums[idx] < 0: dups.append(abs(i)) else: nums[idx] *= -1 return dups
find-all-duplicates-in-an-array
Python 3 Solution, O(n) Time and O(1) Space
AprDev2011
0
65
find all duplicates in an array
442
0.734
Medium
7,854
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1863685/Ez-oror-O(n)-TC-oror-O(1)-SC
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: nums.append(0) n=len(nums) for i in range(n): nums[nums[i]%n]+=n for i in range(n): if nums[i]//n>1: yield(i)
find-all-duplicates-in-an-array
Ez || O(n) TC || O(1) SC
ashu_py22
0
26
find all duplicates in an array
442
0.734
Medium
7,855
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1849032/Python-Solution(memory-less-than-98)-oror-6-lines
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: nums.sort() ans = [] for i in range(1,len(nums)): if nums[i] == nums[i-1]: ans.append(nums[i]) return ans
find-all-duplicates-in-an-array
Python Solution(memory less than 98%) || 6 lines
MS1301
0
124
find all duplicates in an array
442
0.734
Medium
7,856
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1748338/Similar-to-find-the-duplicate-number
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: # Creating a list to return _return = [] # Going through all the list for i, j in enumerate(nums): # Making the index +ve if negative if j < 0: j *= -1 # Making the value there -ve [We can have only +ve values] nums[j-1] *= -1 # Checking if it is still +ve; means we found the number if nums[j-1] > 0: _return.append(j) return _return
find-all-duplicates-in-an-array
Similar to find the duplicate number
funnybacon
0
125
find all duplicates in an array
442
0.734
Medium
7,857
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1628007/Python-3-solution
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: res = [] nums.sort() for i in range(len(nums)-1): if nums[i] == nums[i+1]: res.append(nums[i]) return res
find-all-duplicates-in-an-array
Python 3 solution
user8445t
0
47
find all duplicates in an array
442
0.734
Medium
7,858
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1506347/Faster-than-99.9-using-Counter
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: ans = [] for i,j in Counter(nums).items(): if j == 2: ans.append(i) return ans
find-all-duplicates-in-an-array
Faster than 99.9% using Counter
dikshant14
0
29
find all duplicates in an array
442
0.734
Medium
7,859
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1506135/2-Simple-Python-Solutions-You-Can-Actually-Understand!-Constant-extra-space-in-one-of-them!
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: for n in nums: key = abs(int(n)) - 1 nums[key] *= -1 if nums[key] > 0: nums[key] += 0.1 return [i + 1 for i, n in enumerate(nums) if n > 0 and n % 1]
find-all-duplicates-in-an-array
2 Simple Python Solutions You Can Actually Understand! Constant extra space in one of them! 🚀
Cavalier_Poet
0
72
find all duplicates in an array
442
0.734
Medium
7,860
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1506135/2-Simple-Python-Solutions-You-Can-Actually-Understand!-Constant-extra-space-in-one-of-them!
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: return collections.Counter(nums) - collections.Counter(set(nums))
find-all-duplicates-in-an-array
2 Simple Python Solutions You Can Actually Understand! Constant extra space in one of them! 🚀
Cavalier_Poet
0
72
find all duplicates in an array
442
0.734
Medium
7,861
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/1038430/simple-of-simple
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: # 1. put hash set # 2. if exist then add result list s = set() result = [] for n in nums: if n in s: result.append(n) else: s.add(n) return result # time: O(N) # space: O(N)
find-all-duplicates-in-an-array
simple of simple
seunggabi
0
88
find all duplicates in an array
442
0.734
Medium
7,862
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/779229/Python3-(faster-than-99)
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: d = collections.Counter(nums) ans=[] for num,count in d.items(): if count==2: ans.append(num) return ans
find-all-duplicates-in-an-array
Python3 (faster than 99%)
harshitCode13
0
62
find all duplicates in an array
442
0.734
Medium
7,863
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/779229/Python3-(faster-than-99)
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: ans=[] for num in nums: if nums[abs(num)-1]>0: nums[abs(num)-1] = -nums[abs(num)-1] else: ans.append(abs(num)) return ans
find-all-duplicates-in-an-array
Python3 (faster than 99%)
harshitCode13
0
62
find all duplicates in an array
442
0.734
Medium
7,864
https://leetcode.com/problems/find-all-duplicates-in-an-array/discuss/777028/Easy-Python-Solution-380ms-Faster-than-80
class Solution: def findDuplicates(self, nums: List[int]) -> List[int]: res = [] nums.sort() for i in range(len(nums)-1): if nums[i] == nums[i+1]: res.append(nums[i]) return res
find-all-duplicates-in-an-array
Easy Python Solution, 380ms Faster than 80%
Venezsia1573
0
40
find all duplicates in an array
442
0.734
Medium
7,865
https://leetcode.com/problems/string-compression/discuss/1025555/Python3-Simple-and-Intuitive
class Solution: def compress(self, chars: List[str]) -> int: if not chars: return 0 mychar = chars[0] count = 0 length = len(chars) chars.append(" ") # Append a space so last char group is not left out in loop for i in range(length+1): #+1 for extra space char we added char = chars.pop(0) if char == mychar: #if same character then just increase the count count += 1 else: if count == 1: #if not same then append the char to chars chars.append(mychar) #if count is 1 don't append count elif count > 1: chars.append(mychar) chars += (list(str(count))) #if count > 1 append count as a string mychar = char #update mychar as the new different char in chars count = 1 #reset count to 1 as we have already read the new char return len(chars) #since all previous are popped, only the answer remains in chars now
string-compression
Python3 Simple and Intuitive
upenj
10
1,800
string compression
443
0.489
Medium
7,866
https://leetcode.com/problems/string-compression/discuss/2830228/constant-space-complexity
class Solution: def compress(self, chars: List[str]) -> int: if(len(chars)==1): return 1 ans=[] c=None ct=0 i=0 for a in chars: if(a!=c): if(ct>1): x=str(ct) for m in x: chars[i]=m i+=1 chars[i]=a i+=1 ct=1 c=a else: ct+=1 if(ct==1): return i x=str(ct) for m in x: chars[i]=m i+=1 return i
string-compression
constant space complexity
droj
5
85
string compression
443
0.489
Medium
7,867
https://leetcode.com/problems/string-compression/discuss/1549116/Python-%3A-3-pointers-solution
class Solution: def compress(self, chars: List[str]) -> int: res=l=r=0 while l<len(chars): while r<len(chars) and chars[l]==chars[r]: r+=1 temp=chars[l]+str(r-l) if r-l>1 else chars[l] for c in temp: chars[res]=c res+=1 l=r return res
string-compression
Python : 3 pointers solution
SeraphNiu
2
273
string compression
443
0.489
Medium
7,868
https://leetcode.com/problems/string-compression/discuss/1396473/98-faster-Python-solution-(easy-understand)
class Solution: def compress(self, chars): if len(chars) < 2: return len(chars) outputs, last_char, count = [chars[0]], chars[0], 1 for char in chars[1:]: if last_char == char: count += 1 else: if count > 1: outputs.append(str(count)) outputs.append(char) count = 1 last_char = char if count > 1: outputs.append(str(count)) out = list(''.join(outputs)) for i in range(len(out)): chars[i] = out[i] return len(out)
string-compression
98% faster Python solution (easy understand)
bob23
2
603
string compression
443
0.489
Medium
7,869
https://leetcode.com/problems/string-compression/discuss/1396473/98-faster-Python-solution-(easy-understand)
class Solution: def compress(self, chars): if len(chars) < 2: return len(chars) last_char, count, idx = chars[0], 1, 1 for char in chars[1:]: if last_char == char: count += 1 else: if count > 1: chars[idx:idx+len(str(count))] = str(count) idx += len(str(count)) chars[idx], idx, count = char, idx + 1, 1 last_char = char if count > 1: chars[idx:idx+len(str(count))] = str(count) idx += len(str(count)) return idx
string-compression
98% faster Python solution (easy understand)
bob23
2
603
string compression
443
0.489
Medium
7,870
https://leetcode.com/problems/string-compression/discuss/1711624/python3-two-pointers-sliding-window-easy-to-understand-linear-time-O(n)-in-place
class Solution: def compress(self, chars: List[str]) -> int: left = right = 0 n = len(chars) count = 0 result = [] index = 0 while right < n: if chars[right] == chars[left]: count += 1 right += 1 else: chars[index] = chars[left] if count > 1: for c in str(count): index += 1 chars[index] = c index += 1 count = 0 left = right chars[index] = chars[left] if count > 1: for c in str(count): index += 1 chars[index] = c if index < n - 1: del chars[index + 1 :] return len(chars)
string-compression
python3 two pointers sliding window, easy to understand, linear time O(n) in place
carlo_duan
1
105
string compression
443
0.489
Medium
7,871
https://leetcode.com/problems/string-compression/discuss/1526721/2-Simple-Python-solutions-with-comments-O(N)-time-and-O(1)-space-(-2-pointer-solutions)
class Solution: def compress(self, chars: List[str]) -> int: s="" if len(chars)<=1: return len(chars) p1=writePointer=0 p2=1 count=1 #initial count set to 1 while p2<=len(chars): if p2!=len(chars) and chars[p2]==chars[p1] : #if same char as previous just increment count count+=1 else: chars[writePointer]=chars[p1] #if p2!=len(chars) else chars[p2-1] writePointer+=1 if count>1: #now add the count since its bigger than 1 stringCount=(str(count)) for i in range(len(stringCount)): #for loop for cases like ["a","b","12"] --> should be ["a","b","1","2"] chars[writePointer]=stringCount[i] writePointer+=1 p1=p2 #now new previous is p2 count=1 #restart count p2+=1 return writePointer
string-compression
2 Simple Python 🐍 solutions with comments O(N) time and O(1) space ( 2-pointer solutions)
InjySarhan
1
390
string compression
443
0.489
Medium
7,872
https://leetcode.com/problems/string-compression/discuss/1526721/2-Simple-Python-solutions-with-comments-O(N)-time-and-O(1)-space-(-2-pointer-solutions)
class Solution: def compress(self, chars: List[str]) -> int: s="" if len(chars)<=1: return len(chars) p1=0 p2=1 count=1 #initial count set to 1 while p2<len(chars): if chars[p2]==chars[p1]: #if same char as previous just increment count count+=1 else: s=s+chars[p1]+str(count) if count>1 else s+chars[p1] #now add the char to s if count==1 dont add count p1=p2 #now new previous is p2 count=1 #restart count p2+=1 s=s+chars[p2-1]+str(count) if count>1 else s+chars[p2-1] #because the last char and count where not added as we exit the loop before adding it for i in range(len(s)): #this is just to change the input array and then return len(s) as required in the problem chars[i]=s[i] return len(s)
string-compression
2 Simple Python 🐍 solutions with comments O(N) time and O(1) space ( 2-pointer solutions)
InjySarhan
1
390
string compression
443
0.489
Medium
7,873
https://leetcode.com/problems/string-compression/discuss/1437530/Python3Python-Simple-intuitive-solution-w-comments
class Solution: def compress(self, chars: List[str]) -> int: n = len(chars) if n > 1: # insert counts like one char/digit at a time def insertCounts(chars: List[str], counts: int): if counts > 1: # only insert more than one occurence for count in str(counts): chars.append(str(count)) return # Add compressed data at the end of the # given array counts = 1 prev = "" while n: # scan for original data # first character is always the next # character, as we are deleting character # which is scanned if prev != chars[0]: insertCounts(chars, counts) chars.append(chars[0]) prev = chars[0] counts = 1 else: counts = counts + 1 # Delete the scanned character del chars[0] # Decrement n = n-1 # Last operation insertCounts(chars, counts) # update length n = len(chars) return n
string-compression
[Python3/Python] Simple intuitive solution w/ comments
ssshukla26
1
403
string compression
443
0.489
Medium
7,874
https://leetcode.com/problems/string-compression/discuss/846755/Python3-two-pointers
class Solution: def compress(self, chars: List[str]) -> int: i = ii = 0 cnt = 1 for i in range(len(chars)): if i+1 == len(chars) or chars[i] != chars[i+1]: chars[ii] = chars[i] ii += 1 if cnt > 1: chars[ii: (ii := ii+len(str(cnt)))] = str(cnt) cnt = 0 cnt += 1 return ii
string-compression
[Python3] two pointers
ye15
1
166
string compression
443
0.489
Medium
7,875
https://leetcode.com/problems/string-compression/discuss/2845142/Better-than-99-Python-Solution
class Solution: def compress(self, chars: List[str]) -> int: i = 0 length = len(chars) if length == 1: return len(chars) s = "" while i < length: cnt = 1 j = i + 1 s += chars[i] while j < length and chars[i] == chars[j]: cnt += 1 j += 1 if cnt > 1: s += str(cnt) i = j chars[:] = list(s) return len(chars)
string-compression
Better than 99% Python Solution
khaled_achech
0
3
string compression
443
0.489
Medium
7,876
https://leetcode.com/problems/string-compression/discuss/2705877/90-faster-python-solution
class Solution: def compress(self, chars: List[str]) -> int: res=[] count=1 res.append(chars[0]) for i in range(1,len(chars)): if chars[i]==chars[i-1]: count+=1 if i==len(chars)-1: if count>=10: dummy=[] while count>0: tmp=count%10 dummy.insert(0,tmp) count=count//10 res.extend(dummy) else: res.append(count) else: if count>1: if count>=10: dummy=[] while count>0: tmp=count%10 dummy.insert(0,tmp) count=count//10 res.extend(dummy) else: res.append(count) res.append(chars[i]) else: res.append(chars[i]) count=1 for i in range(0,len(res)): chars[i]=str(res[i]) return len(res)
string-compression
90% faster python solution
kowshick17
0
8
string compression
443
0.489
Medium
7,877
https://leetcode.com/problems/string-compression/discuss/2704405/constant-space-solution-explained
class Solution: def compress(self, chars: List[str]) -> int: back=0#first occurance of a new character ind=0#current length of the list to be returned n =len(chars)#length of list #print(chars) for pos , char in enumerate(chars): #iterating pos =index and char is the char at index=pos if pos==n-1 or char!=chars[pos+1]: #if it is the last character cahracter in the list or the repetion of a character ends here chars[ind]=char #add the char to the list at the current legth ind+=1 #increase in the length of ans if pos>back: #if a chacter is repeated times=pos-back+1 #no of times a character appeared repeatedly st_time=str(times) #string converson of no of times for i in st_time: chars[ind]=i #add the char in num of repeated times ind+=1 #increase in length back=pos+1 #the start of occurance of new char return ind #return the length of the list #print(chars)
string-compression
constant space solution explained
abhayCodes
0
7
string compression
443
0.489
Medium
7,878
https://leetcode.com/problems/string-compression/discuss/2694364/99-Accepted-or-Two-Solutions-or-Easy-to-Understand-or-Python
class Solution(object): def compress(self, chars): currIdx, currStr, currCount = 0, chars[0], 1 for i in range(1, len(chars)): if chars[i] == currStr: currCount += 1 else: if currCount == 1: chars[currIdx] = currStr currIdx += 1 elif currCount < 10: chars[currIdx] = currStr chars[currIdx + 1] = str(currCount) currIdx += 2 else: currCount = str(currCount) chars[currIdx] = currStr currIdx += 1 for j in range(len(currCount)): chars[currIdx] = currCount[j] currIdx += 1 currStr = chars[i] currCount = 1 if currCount == 1: chars[currIdx] = currStr currIdx += 1 elif currCount < 10: chars[currIdx] = currStr chars[currIdx + 1] = str(currCount) currIdx += 2 else: currCount = str(currCount) chars[currIdx] = currStr currIdx += 1 for j in range(len(currCount)): chars[currIdx] = currCount[j] currIdx += 1 return currIdx
string-compression
99% Accepted | Two Solutions | Easy to Understand | Python
its_krish_here
0
20
string compression
443
0.489
Medium
7,879
https://leetcode.com/problems/string-compression/discuss/2694364/99-Accepted-or-Two-Solutions-or-Easy-to-Understand-or-Python
class Solution(object): def compress(self, chars): ansList = [] currStr = chars[0] count = 1 for i in range(1, len(chars)): if currStr == chars[i]: count += 1 else: if count == 1: ansList.append(currStr) elif len(str(count)) > 1: count = str(count) ansList.append(currStr) for j in range(len(count)): ansList.append(count[j]) else: ansList.append(currStr) ansList.append(str(count)) count = 1 currStr = chars[i] if count == 1: ansList.append(currStr) elif len(str(count)) > 1: count = str(count) ansList.append(currStr) for i in range(len(count)): ansList.append(count[i]) else: ansList.append(currStr) ansList.append(str(count)) for i in range(len(ansList)): chars[i] = ansList[i] return len(ansList)
string-compression
99% Accepted | Two Solutions | Easy to Understand | Python
its_krish_here
0
20
string compression
443
0.489
Medium
7,880
https://leetcode.com/problems/string-compression/discuss/2630209/Python-faster-than-65-easy-to-understand
class Solution: def compress(self, chars: List[str]) -> int: s = '' ptr = 0 ptr_next = 0 while ptr < len(chars): letter_counter = 0 while (ptr_next < len(chars) and chars[ptr] == chars[ptr_next]): letter_counter += 1 ptr_next += 1 if letter_counter > 1: s += str(chars[ptr]) + str(letter_counter) ptr += 1 for num in str(letter_counter): chars[ptr] = num ptr += 1 else: s += str(chars[ptr]) ptr += 1 ptr = ptr_next chars[:] = s return len(s)
string-compression
Python faster than 65% - easy to understand
roslan
0
35
string compression
443
0.489
Medium
7,881
https://leetcode.com/problems/string-compression/discuss/2600909/Python3-Simple-Solution
class Solution: def compress(self, chars: List[str]) -> int: pre = "" res = [] count = 1 for c in chars: if c != pre: if count != 1: for i in str(count): res.append(i) res.append(c) pre = c count = 1 else: count += 1 if count != 1: for i in str(count): res.append(i) n = len(res) chars[:] = res return n
string-compression
Python3 Simple Solution
kchiranjeevi
0
161
string compression
443
0.489
Medium
7,882
https://leetcode.com/problems/string-compression/discuss/2150014/python-3-oror-simple-solution-oror-O(n)O(1)
class Solution: def compress(self, chars: List[str]) -> int: insert = 0 groupLength = 1 chars.append(' ') for i in range(1, len(chars)): if chars[i] == chars[i - 1]: groupLength += 1 continue chars[insert] = chars[i - 1] insert += 1 if groupLength== 1: continue for digit in str(groupLength): chars[insert] = digit insert += 1 groupLength = 1 return insert
string-compression
python 3 || simple solution || O(n)/O(1)
dereky4
0
301
string compression
443
0.489
Medium
7,883
https://leetcode.com/problems/string-compression/discuss/1916418/Python-easy-understanding-solution-with-comment
class Solution: def compress(self, chars: List[str]) -> int: chars += [None] # Trick to deal with the last element. cur = chars[0] count = 0 # count: record the times one element had appeared. slow = 0 # slow: the idx ready to be modified. for i, char in enumerate(chars): if char != cur: # When we meet a new element, chars[slow] = cur # we modify char[slow] to cur. cur = char # Update cur to new element. slow += 1 # Update the position of slow. if count == 1: # If the previous element only appear once, skip below. continue for c in str(count): # Modify chars[slow] to appear times. chars[slow] = c slow += 1 count = 1 # Reset count = 1 because we met the new element. elif char == cur: count += 1 return slow
string-compression
Python easy - understanding solution with comment
byroncharly3
0
219
string compression
443
0.489
Medium
7,884
https://leetcode.com/problems/string-compression/discuss/1630901/Easy-pyhton3-solution
class Solution: def compress(self, chars: List[str]) -> int: n=len(chars) i=0 j=0 while j<len(chars): while j<len(chars)-1 and chars[j]==chars[j+1]: j+=1 freq=(j-i+1) if i==j: j+=1 i=j continue while j-i!=0: chars.pop(j) j-=1 for val in str(freq): j+=1 chars.insert(j,val) j+=1 i=j return len(chars)
string-compression
Easy pyhton3 solution
Karna61814
0
125
string compression
443
0.489
Medium
7,885
https://leetcode.com/problems/string-compression/discuss/1560592/Python3-Two-pointers-solution
class Solution: def compress(self, chars: List[str]) -> int: idx = 0 last_idx_for_insert = 0 while idx < len(chars): char_cnt = 1 while idx < len(chars) - 1 and chars[idx] == chars[idx + 1]: char_cnt += 1 idx += 1 chars[last_idx_for_insert] = chars[idx] last_idx_for_insert += 1 char_cnt_lst = [d for d in str(char_cnt)] if len(char_cnt_lst) > 1 or char_cnt_lst[0] != '1': for digit_str in char_cnt_lst: chars[last_idx_for_insert] = digit_str last_idx_for_insert += 1 idx += 1 return len(chars[:last_idx_for_insert])
string-compression
[Python3] Two-pointers solution
maosipov11
0
143
string compression
443
0.489
Medium
7,886
https://leetcode.com/problems/string-compression/discuss/1358129/Python-Comprehension
class Solution: def compress(self, chars: List[str]) -> int: res = [] count = 1 for i in range(1, len(chars)): if chars[i - 1] == chars[i]: count += 1 else: res.append(chars[i - 1]) if count > 1: L = [_ for _ in str(count)] res += L count = 1 res.append(chars[-1]) if count > 1: L = [_ for _ in str(count)] res += L count = 1 chars[:] = res return len(chars)
string-compression
[Python] Comprehension
Sai-Adarsh
0
158
string compression
443
0.489
Medium
7,887
https://leetcode.com/problems/string-compression/discuss/343081/Python-3-(beats-~100)-(-O(n)-speed-)-(-O(1)-space-)-(-in-place-)-(seven-lines)
class Solution: def compress(self, C: List[str]) -> int: if len(C) <= 1: return c, i, _ = 1, 0, C.append(" ") while C[i] != " ": if C[i] == C[i+1]: c += 1 elif c > 1: C[i+2-c:i+1], i, c = list(str(c)), i + 1 - c + len(list(str(c))), 1 i += 1 del C[-1] - Junaid Mansuri
string-compression
Python 3 (beats ~100%) ( O(n) speed ) ( O(1) space ) ( in place ) (seven lines)
junaidmansuri
0
891
string compression
443
0.489
Medium
7,888
https://leetcode.com/problems/add-two-numbers-ii/discuss/486730/Python-Using-One-Stack-Memory-Usage%3A-Less-than-100
class Solution: def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode: n1 = n2 = 0 ptr1, ptr2 = l1, l2 stack = [] while ptr1: n1 += 1; ptr1 = ptr1.next while ptr2: n2 += 1; ptr2 = ptr2.next max_len = max(n1, n2) while max_len: a = b = 0 if max_len <= n1: a = l1.val; l1 = l1.next if max_len <= n2: b = l2.val; l2 = l2.next stack.append(a + b) max_len -= 1 sumval, head = 0, None while stack or sumval: if stack: sumval += stack.pop() node = ListNode(sumval % 10) node.next = head head = node sumval //= 10 return head
add-two-numbers-ii
Python - Using One Stack [Memory Usage: Less than 100%]
mmbhatk
11
766
add two numbers ii
445
0.595
Medium
7,889
https://leetcode.com/problems/add-two-numbers-ii/discuss/846777/Python3-two-approaches
class Solution: def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode: def fn(node): """Return number represented by linked list.""" ans = 0 while node: ans = 10*ans + node.val node = node.next return ans dummy = node = ListNode() for x in str(fn(l1) + fn(l2)): node.next = ListNode(int(x)) node = node.next return dummy.next
add-two-numbers-ii
[Python3] two approaches
ye15
6
522
add two numbers ii
445
0.595
Medium
7,890
https://leetcode.com/problems/add-two-numbers-ii/discuss/846777/Python3-two-approaches
class Solution: def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode: def fn(node): """Reverse a linked list.""" prev = None while node: prev, node.next, node = node, prev, node.next return prev l1, l2 = fn(l1), fn(l2) # reverse l1 &amp; l2 carry = 0 dummy = node = ListNode() while carry or l1 or l2: if l1: carry += l1.val l1 = l1.next if l2: carry += l2.val l2 = l2.next carry, x = divmod(carry, 10) node.next = node = ListNode(x) return fn(dummy.next)
add-two-numbers-ii
[Python3] two approaches
ye15
6
522
add two numbers ii
445
0.595
Medium
7,891
https://leetcode.com/problems/add-two-numbers-ii/discuss/1707722/Python-Simple-Stack-Solution-oror-85-Runtime
class Solution: def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]: stack1, stack2, curr1, curr2, head, carry = [], [], l1, l2, ListNode(), 0 while curr1 is not None: stack1.append(curr1.val) curr1 = curr1.next while curr2 is not None: stack2.append(curr2.val) curr2 = curr2.next l1, l2 = len(stack1), len(stack2) for _ in range(max(l1, l2)): a = 0 if l1 <= 0 else stack1.pop() b = 0 if l2 <= 0 else stack2.pop() l1 -= 1 l2 -= 1 sum = a+b+carry carry = sum//10 temp = ListNode(sum%10, head.next) head.next = temp if carry != 0: temp = ListNode(carry, head.next) head.next = temp return head.next
add-two-numbers-ii
Python Simple Stack Solution || 85% Runtime
anCoderr
3
204
add two numbers ii
445
0.595
Medium
7,892
https://leetcode.com/problems/add-two-numbers-ii/discuss/333986/Python-faster-than-99.88-(64ms)
class Solution: def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode: num1 = "" num2 = "" # loop through the first linked list, storing the values in the num1 variable while l1 is not None: num1 += str(l1.val) l1 = l1.next # follows same process as above while l2 is not None: num2 += str(l2.val) l2 = l2.next # calculate the sum of the values that we just obtained and store it as a string summation = str(int(num1) + int(num2)) # make the head of the node the first number in the summation string head = ListNode(summation[0]) # create a new reference to the head so we can manipulate the linked list but not lose the original reference to the head temp = head # loop through the remaining numbers in the summation string, each time creating a new node for val in summation[1:]: temp.next = ListNode(val) temp = temp.next # return the original reference to the head return head
add-two-numbers-ii
Python faster than 99.88% (64ms)
softbabywipes
3
679
add two numbers ii
445
0.595
Medium
7,893
https://leetcode.com/problems/add-two-numbers-ii/discuss/2661663/Three-different-solutions-python.-HE-COULD-DO-THIS-FOR-WEEKS-SEE-THE-CONTINUATION-IN-THE-SOURCE.
class Solution1: def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]: def down_up(c1, c2): if c1.next: tail, rem = down_up(c1.next, c2.next) else: tail, rem = None, 0 if c1.val >= 0 and c2.val >= 0: s = c1.val + c2.val + rem elif c1.val >= 0: s = c1.val + rem else: s = c2.val + rem if s > 9: h, rem = ListNode(s - 10), 1 else: h, rem = ListNode(s), 0 h.next = tail return h, rem len_1, len_2 = 0, 0 l1_c, l2_c = l1, l2 while l1_c: l1_c = l1_c.next len_1 += 1 while l2_c: l2_c = l2_c.next len_2 += 1 if len_1 != len_2: dummy_h = dummy = ListNode(-1) for i in range(abs(len_1 - len_2) - 1): dummy.next = ListNode(-1) dummy = dummy.next if len_1 < len_2: dummy.next = l1 l1 = dummy_h elif len_2 < len_1: dummy.next = l2 l2 = dummy_h l, rem = down_up(l1, l2) if rem: head = ListNode(1, l) else: head = l return head class Solution2: def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]: def linked2ordinary(l): l_l = [] while l: l_l.append(l.val) l = l.next return l_l l1_l, l2_l = linked2ordinary(l1)[::-1], linked2ordinary(l2)[::-1] answer = [] reminder = 0 i, j = 0, 0 while i < len(l1_l) and j < len(l2_l): s = l1_l[i] + l2_l[j] + reminder if s > 9: answer.append(s - 10) reminder = 1 else: answer.append(s) reminder = 0 i, j = i + 1, j + 1 while i < len(l1_l): s = l1_l[i] + reminder if s > 9: answer.append(s - 10) reminder = 1 else: answer.append(s) reminder = 0 i += 1 while j < len(l2_l): s = l2_l[j] + reminder if s > 9: answer.append(s - 10) reminder = 1 else: answer.append(s) reminder = 0 j += 1 if reminder: answer.append(1) head = curr = ListNode() answer = answer[::-1] for i in range(len(answer)): curr.val = answer[i] if i < len(answer) - 1: curr.next = ListNode() curr = curr.next return head class Solution3: def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]: def reverse(l): h = curr = l prev = None while curr: tmp = curr.next curr.next = prev prev, curr = curr, tmp return prev l1, l2 = reverse(l1), reverse(l2) head = ListNode() curr = head while l1 and l2: curr.val = l1.val + l2.val if l1.next and l2.next: curr.next = ListNode() curr = curr.next l1, l2 = l1.next, l2.next if l1 or l2: curr.next = l1 or l2 curr = head last_item = None reminder = 0 while curr: if reminder + curr.val > 9: curr.val = reminder + curr.val - 10 reminder = 1 else: curr.val += reminder reminder = 0 if not curr.next: last_item = curr curr = curr.next if reminder: last_item.next = ListNode(1) return reverse(head)
add-two-numbers-ii
Three different solutions python. HE COULD DO THIS FOR WEEKS, SEE THE CONTINUATION IN THE SOURCE.
Yaro1
2
181
add two numbers ii
445
0.595
Medium
7,894
https://leetcode.com/problems/add-two-numbers-ii/discuss/1817560/Python-3-Easy-to-understand
class Solution: def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]: # 2. Add Two Numbers dummy = ListNode(0) curr = dummy carry = 0 # reverse l1 and l2 l1, l2 = self.reverse(l1), self.reverse(l2) while l1 or l2 or carry: v1 = l1.val if l1 else 0 v2 = l2.val if l2 else 0 # new digit val = v1 + v2 + carry carry, val = val // 10, val % 10 curr.next = ListNode(val) # update pointer l1 = l1.next if l1 else None l2 = l2.next if l2 else None curr = curr.next # reverse back the result return self.reverse(dummy.next) # 206. Reverse Linked List def reverse(self, head): prev, curr = None, head while curr: # swap node nxt = curr.next curr.next = prev # update pointers prev, curr = curr, nxt return prev
add-two-numbers-ii
[Python 3] Easy to understand
flatwhite
1
81
add two numbers ii
445
0.595
Medium
7,895
https://leetcode.com/problems/add-two-numbers-ii/discuss/1177372/Python-or-Faster-than-99.47
class Solution: def list2int(self, lst): num = "" while lst: num += str(lst.val) lst = lst.next return int(num) def int2list(self, num): lst = list(map(int, str(num))) begin = ListNode(0) end = begin for i in lst: end.next = ListNode(i) end = end.next return begin.next def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode: num1 = self.list2int(l1) num2 = self.list2int(l2) ans = num1 + num2 return self.int2list(ans)
add-two-numbers-ii
Python | Faster than 99.47%
AriefPA
1
87
add two numbers ii
445
0.595
Medium
7,896
https://leetcode.com/problems/add-two-numbers-ii/discuss/1064322/Python-solution-using-two-stacks.-Beats-95
class Solution: def addTwoNumbers(self, l1: ListNode, l2: ListNode) -> ListNode: s1 = [] s2 = [] res = ListNode(0) while l1: s1.append(l1.val) l1 = l1.next while l2: s2.append(l2.val) l2 = l2.next sum_n = 0 carry = 0 while s1 or s2: n1 = s1.pop() if s1 else 0 n2 = s2.pop() if s2 else 0 sum_n = carry + n1 + n2 carry = sum_n // 10 res.val = sum_n % 10 head = ListNode(sum_n // 10) head.next = res res = head return res.next if res.val == 0 else res
add-two-numbers-ii
Python solution using two stacks. Beats 95%
Pseudocoder_Ravina
1
94
add two numbers ii
445
0.595
Medium
7,897
https://leetcode.com/problems/add-two-numbers-ii/discuss/2751034/Python-and-Golang-Solution
class Solution: def reverse(self, head: ListNode) -> ListNode: current_node = head previous_node = None while current_node: next_node = current_node.next current_node.next = previous_node previous_node = current_node current_node = next_node return previous_node def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]: reversed_l1 = self.reverse(l1) reversed_l2 = self.reverse(l2) result = ListNode(-1) dummy = result increment = 0 while reversed_l1 and reversed_l2: total = reversed_l1.val + reversed_l2.val + increment increment = 0 if 10 <= total: increment += 1 total -= 10 dummy.next = ListNode(total) while dummy.next: dummy = dummy.next reversed_l1 = reversed_l1.next reversed_l2 = reversed_l2.next while reversed_l1: total = reversed_l1.val + increment increment = 0 if 10 <= total: increment += 1 total -= 10 dummy.next = ListNode(total) while dummy.next: dummy = dummy.next reversed_l1 = reversed_l1.next while reversed_l2: total = reversed_l2.val + increment increment = 0 if 10 <= total: increment += 1 total -= 10 dummy.next = ListNode(total) while dummy.next: dummy = dummy.next reversed_l2 = reversed_l2.next if 0 < increment: dummy.next = ListNode(1) return self.reverse(result.next)
add-two-numbers-ii
Python and Golang Solution
namashin
0
3
add two numbers ii
445
0.595
Medium
7,898
https://leetcode.com/problems/add-two-numbers-ii/discuss/2681077/Python-O(1)-space-O(N)-time-recursion.
class Solution: def addTwoNumbers(self, l1: Optional[ListNode], l2: Optional[ListNode]) -> Optional[ListNode]: def _get_length(node1, node2): n1 = 1 n2 = 1 while node1.next or node2.next: if node1.next: n1 += 1 node1 = node1.next if node2.next: n2 += 1 node2 = node2.next return n1, n2 def _helper(n1, n2, nn1, nn2, depth): if n1.next is None and n2.next is None: n1.val += n2.val elif n1.next is not None or n2.next is not None: if depth <= nn1 - nn2: carry = _helper(n1.next, n2, nn1, nn2, depth + 1) else: carry = _helper(n1.next, n2.next, nn1, nn2, depth + 1) n1.val += n2.val n1.val += carry carry = n1.val // 10 n1.val %= 10 return carry ln1, ln2 = _get_length(l1, l2) flag = ln1 > ln2 carry = (_helper(l1, l2, ln1, ln2, 1) if flag else _helper(l2, l1, ln2, ln1, 1)) if not carry: return (l1 if flag else l2) ans = ListNode(val=carry, next=(l1 if flag else l2)) return ans
add-two-numbers-ii
Python O(1) space, O(N) time, recursion.
jithindmathew56
0
33
add two numbers ii
445
0.595
Medium
7,899